1. Technical Field
The present invention relates to a method for controlling a telephone conversation in a radio mobile telephone, and more particularly, to a method capable of automatically dialing input telephone numbers.
2. Background Art
Generally, conventional radio mobile telephone systems include portable telephones and radio telephones for use in vehicles. A basic radio mobile telephone system usually consists of three parts: a mobile telephone unit, a cell site, and a mobile telephone switching office (MTSO) with connections to link the three subsystems. The mobile telephone unit contains a controller, a transceiver, and an antenna system. The cell site provides interface between the MTSO and the mobile telephone units. The MTSO which is the central coordinating element for all cell sites, contains the cellular processor and cellular switch. The MTSO interfaces with telephone company zone offices, controls call processing, and handles billing activities. The radio and high-speed data links connect the three subsystems. Each mobile telephone unit can use only one channel at a time for its communication link, but the channel is not fixed; it can be any channel in the entire band of channels assigned by the serving area, with each cell site having multichannel capabilities that can connect simultaneously to many mobile telephone units.
The MTSO is the heart of the cellular mobile system. Its cellular switch, which can be either analog or digital, switches calls to connect mobile subscribers to other mobile subscribers and to the nationwide telephone network. The radio link carries the voice and signaling between the mobile unit and the cell site. The high-speed data links, however, can not be transmitted over the standard telephone trunks and therefore must use either microwave links or wire lines. Microwave radio links or wire lines carry both voice and data between the cell site and the MTSO.
The mobile telephone unit, as described above, generally contains a controller, a transceiver, and an antenna system. The transceiver includes a frequency synthesizer to establish a radio channel with a nearby base station located in a cell site of the mobile telephone system in a manner well known in the art under the control of the controller. An audio circuit is also used for coupling a speaker and a microphone to the transceiver when the connection is established with the base station located in the cell site. A telephone keypad is also provided to allow an operator to dial a telephone number requesting connection with the base station. The telephone keypad typically contains a series of keys or push buttons designated as "1" to "0" and a "*" and a "#" key. For visually assisting an operator to enter digits for the purpose of dialing a telephone number of a called subscriber, a display unit is connected to the controller to display dialing and other information on the cellular phone.
When a telephone call is desired, an operator must first enter a telephone number of a called subscriber through the keypad. Once the telephone number and its corresponding digit number is stored in a memory and displayed through the display unit, the operator is then required to press a "SEND" key after the telephone number of a called subscriber has been dialed in order to transmit such a telephone number to the telephone network and to inform the network that a connection is desired. There are known dialing features that may be incorporated into such a conventional mobile telephone system in order to simplify a dialing operation such as an automatic dialing technique disclosed, for example, in U.S. Pat. No. 5,493,604 for Portable Telephone Set With Automatic Dialing Feature issued to Hirayama, a speed dialing technique disclosed, for example, in U.S. Pat. No. 5,349,629 for Portable Telephone With Speed Dialing issued to Kumano, U.S. Pat. No. 5,305,372 for Mobile Unit With Speed Dialing Feature For Cellular Telephone Network issued to Tomiyori, and U.S. Pat. No. 5,267,308 for Speed Dialing Method For A Telephone Unit issued to Jokinen et al., and a memory enhanced dialing technique disclosed, for example in U.S. Pat. No. 5,402,481 for Abbreviated And Enhanced Dialing Apparatus And Methods Particularly Adapted Cellular Or Other Types Of Telephone Systems issued to Waldman and U.S. Pat. No. 5,384,825 for Method For Memory Dialing For Cellular Telephones issued to Dillard et al. I have observed that even if any one of these enhanced dialing techniques is incorporated into a typical mobile telephone unit, when a telephone number is dialed in its abbreviated form, whether for speed dialing or memory dialing, an operator is still required to press a "SEND" for transmission to the telephone network in order to inform the network that a connection is desired. This manual requirement can be cumbersome, and consequently further improvement can be contemplated.